[MI2600]

You can buy the choke conversions at most parts stores. It just replaces the outer ceramic choke housing so a cable can be used.

[Jmark]

Personally, I like the electric chokes. Also sounds like the accel pump is indeed dead or possibly plugged. The carb probably isn't too hard to do if you have some carb experience. If you don't, call around and find someone good and take yours in to be fixed. Or find a friend to help that has experience.
Do NOT under any circumstances buy a rebuilt carb from the auto parts stores!!! Most are junk and have been sitting too long to be good for the long haul.

Mark

[2-manytoyzs]

Good answer jmark. Rebuilts (most after-market) are assembled in bulk and can have any of the internal parts such as springs and metering components all the same. Factory rebuilts are more application specific. I recommend using the electric choke. Hook up the hot lead to the choke from the field lead of the alternator so the choke is only powered when the engine is running. BTW fuel cant run out of the fuel bowl back into the fuel line so it cant be a bad pump. A bad pump will not deliver enough fuel at high speeds, or will leak internally into the crankcase and dilute the oil, or leak externally thru the weep hole and onto the ground.